Galileo Galilei

Pioneer Space Exploration


Galileo was born on the 15th of February 1564 near Pisa, Italy.

Discoveries and Achievements

Galileo attended the University of Pisa and studied medicine but then switched to philosophy and mathematics. In 1589 he became a professor of mathematics at Pisa University.

In 1609 Galileo heard about the invention of the telescope in Holland and without seeing an example, created and even better model himself. He made many discoveries and these included the finding of mountains and valleys on the moon, sunspots, the phases of Venus and Jupiters four largest moons (Io, Europa, Claisto and Ganymede).

The Battle with Hersey

In 1614, Galileo was accused of hersey. Hersey was the crime of misleading the churchs' followers in any way. Galileo believed that the earth revolved around the sun. (the Copinican Therory) instead of the the sun revolving around earth, which was the churchs' therory. Even though hersey was a crime punishable by death, He managed to get off with only strict instructions never to teach or advocate the Copinican Therory again. However, Galileo was not one to learn from his mistakes imediately. Again, in 1632 he was comdemned for hersey after the publication of his new book Dialogue Between the Two Cheif World Systems. This time he didn't get off so easily. Galileo was sentenced to life imprisonment, but this was reduced to him being locked away in his home for the rest of his life.

Discovery of Jupiter's moons

On January 7, 1610, he turned his telescope towards Jupiter, and discovered three small, bright stars near the planet. One was off to the west, the other two were to the east, all three in a straight line. The following evening, Galileo once again took a look at Jupiter, and found that all three of the "stars" were now west of the planet, still in a straight line! This was how he came to the conclusion that these stars were actually moons of Jupiter because the rotation was that of a moon and its orbit was around the planet.


Galileo Galilie died on the 8th of January 1642.